Field of the Disclosure
This document relates to an organic light emitting diode device, and more particularly, to an organic light emitting diode device including a pyrene compound.
Discussion of the Related Art
In recent years, with the development of multi-media, the importance of a flat panel display (FPD) has increased. To satisfy the demand, various displays such as a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and an organic light emitting diode device have been put to practical use.
Particularly, the organic light emitting diode device is a self-emissive device, which represents fast response speed of 1 ms or less and low power consumption. Further, since the organic light emitting diode device has an excellent viewing angle, the organic light emitting diode device is beneficial as a moving picture display medium regardless of the size of a device. In addition, since the organic light emitting diode device may be fabricated at a low temperature and a manufacturing process thereof is simple based on an existing semiconductor process technique, it is spotlighted as a next-generation flat panel display.
The organic light emitting diode device includes a cathode, an anode and an organic emission layer interposed between the cathode and the anode. An electron provided from the cathode is combined with a hole provided from the anode at the emission layer to form an exciton. The exciton is transited into a ground state from an excited state, thereby emitting light.
The organic light emitting diode device has been developed as various structures. Among them, a tandem organic light emitting diode device manufacturing by stacking a plurality of emission layers has been developed. The organic light emitting diode device has a plurality of stack structures including a hole injection layer/hole transport layer/emission layer/electron transport layer/electron injection layer. Particularly, a charge generation layer including N type and P type charge generation layers is formed between the stacks, so that a charge is generated or the charge is injected into each emission layer.
However, in the charge generation layer, an injection characteristic of an electron generated by charge generation at an interfacial surface of a hole injection layer adjacent to a P type charge generation layer due to an energy level difference between an N type charge generation layer and the P type charge generation layer in the N type charge generation layer is deteriorated. When the N type charge generation layer according to the related art is doped with alkaline metal, the alkaline metal is diffused into the P type charge generation layer so that life span of the device is deteriorated.